Milling a hollow part, and in particular milling grooves in the walls of cylindrical tubes, is an operation which is conventionally performed by qualified workmen using conventional milling tools. When a tube is being milled, the tool is generally carried on a moving support which is displaced during milling to enable the workmen to follow the desired groove contour.
In some applications, and in particular in the nuclear industry, a problem rises since: firstly, the tubes to be machined are generally in the form of fixed pipework already installed on site; and secondly, the site is not necessarily accessible to a workman for example because of proximity to a source of radioactivity. The problem becomes further complicated in some applications by virtue of the fact that the grooves must be milled to an extremely accurate depth, since the sheet or web remaining at the bottom of the groove must be very thin relative to the milling depth, yet it is essential to avoid the groove penetrating at any point into the inside of the tube.
The aim of the present invention is to provide a solution to this problem.